1. Field of the Invention
This invention deals with videocommunications and more particularly with the remote distribution of television channels to subscriber television terminals through a videocommunication cable network.
More precisely, the invention concerns a videocommunication network comprising at least one distribution station serving N subscriber television terminals. The distribution station includes a distribution amplifier for receiving M television channels from a wideband distribution line, and individual channel selectors each receiving the television channels repeated by the distribution amplifier. Each of the subscriber television terminals is connected to the distribution station via a bidirectional wideband transmission medium including a forward line carrying one of the television channels and a backward line carrying a channel address signal.
2. Description of the Prior Art
In known videocommunication networks of this type, an individual television channel selector is ascribed to each subscriber. The number, M, of television channels is decidely smaller than the number, N, of subscriber terminals. In a distribution station that comprises only analog transmission circuitry, each selector is interconnected between one of N distribution amplifier outputs and an input of the forward line of the corresponding transmission medium serving the subscriber terminal.
Selection of one television channel that the subscriber wishes to receive on the TV set is remotely controlled by an address signal carried by the corresponding backward line.
As a result, each selector is programmable remotely so as to retransmit only a desired channel from all the channels delivered by the distribution amplifier. The cost of linking a subscriber terminal to the distribution station is dependent primarily on the cost of the programmable channel selector, which is relatively high.